Compressor apparatus



Dec. 13, 1927. 1,652,747

. w. VAN RIJSWIJK couPREsson APPARATUS Filed Au 1a. 192s S g R & u

' E w Si @o S N h1 m N Q, /p d f i i Hln'in" "il" Il Q iiiiaiiif ,f T: Illllii IHN |11 nl ulllevllul Imaan/lof Patented Dec. 13, 1927.

UNITED STATES VIILLEM VAN RIJSWIJK, OF ENNETBADEN, SWITZERLAND, ASSIGNOR TO AKTIEN- GESELLSCHAFT BROWN BOVERI & CIE.,

COMPANY OF SWITZERLAND.

OF BADEN, SWITZERLAND, A JOINT-STOCK COMPRESSOR APPARATUS.

Application filed August 18, 1926, Serial No. 129,966, and in Germany July 2, 1925.

This invention relates to rotary compressors or blowers, and is ot' particular utility as applied to compressors or blowers which are driven by electric motors.

A general object of the invention is the provision or' an arrangement tor 'facilitating the starting ot rotary compressors, so that the driving motors will not be required to develop excessive torque at starting.

An ancillary object is the provision of an arrangement which will decrease the cost of rotary compressor installations by permitting the use of electrical motors ot the synchronous or squirrel cage types.

Other objects will be pointed out or indi-- cated hereinafter, or will be apparent to one skilled in the art upon an understanding of the invention.

In the accompanying drawing is shown one arrangement in which the invention may be. embodied, but the same is presented for illustration only, and is not to be interpreted as limiting the claims short ot' the true and most comprehensive scope of the invention in the art.

In the drawing,

Fig. `1 is a partside elevational view of a rotary compressor installation, showing the compressor direct connected to an electric motor; 'Y

Fig. 2 is a sectional elevation illustrating a gland closing arrangement and starting mechanism, and

Fig. 3 is a side elevational view of the starting mechanism. y

Electric motors ot the synchronous or squirrel cage induction types possess certain advantages which are highly desirable for the operation of rotary compressors. In the first place, theyV are relatively simple and economical types of motors, and thus contribute to reduction of cost of the installation.' In the second place, since a rotary compressor is a constant speed machine, economical and efficient operation at the rated speed may be most 'convenient-ly attained with motors of those types. However, the starting of rotary compressors, particularly those ot substantial size, involves the accelerating of heavy masses, and thus imposes on the driving motor requirements which motors of the induction or squirrel cage types are not qualified to meet. The synchronous motor, for example, must be y lar 24 is mounted in the sleeve 21 for started under greatly reduced excitation, and has a very low starting torque, while squirrel cage motors, when starting under load, drawA started by suoli motors attheir starting torques and without excessive demands on the current supply. y

The nature of the invention will be ascertained atonce by reference to the illustrative embodiment wherein the reference character .10 designates generally a compressor which Yis driven by a motor 11, which may be of .the induction or squirrel cage induction type, the rotors of the compressor and the motor having direct connection through the shaft 12. The intake of the compressor is designated 14, and its outlet 15, and valves 16 and 17 are providedv whereby both the intake and the outlet may be closed. As a means for reducing the resistance to starting of the compresser, I provide an arrangement for exhausting or partially exhausting the air lfrom the compressor easing. Such means is illustrat-ed by the ejector pump 18 which is connected to the outlet 15 between the valve 17 and the casing, by the pipe 19. The pipe 20 supplies the actuating fluid to the ejector pump 18, whereby the air is withdrawn from the compressor casing. In order to aid in the exhausting of air from the casing, and to hold the partial Vacuum, I provide sealing glands for the casing about the shaft l2, a form being illustrated in Fig. 2. In this illustration the compressor casing is designatedv 10a and is provided with a sleeve 21 encircling the shaft. In this sleeve is mounted a flexible disk or gasket 22 which nor.

mally encircles the shaft loosely. A cam co1- sliding movement axia'lly of the shaft, being held against rotation by engagement of a lug 24a in a groovel in the sleeve. vSprings 25 urge the cam collar 24 away from the gasket 22, but the cam collar has an annular portion 24" adapted for engagement with the gasket 22 so that, upon inward movement of the cam collar, the gasket will be compressed ofthe air from it by the exhausting device 18. It isto be noted that the gasket'or-sealing element 22 acts in the nature of a valve,- andiI that due to the outward; flexure ofthe gasket the inner edge thereof seats on the shaft with thel pressure exteriorly of the compressor casing so that when; the gasket` is flexed' to av greaterdegree into sealing positiomin thegmanner explained, such pres sureY provides further for the holding of the vgasket into close sealing relation with respect to the shaft.

For overcoming'the static inertia of the compressor shaft and rotor, a` simplev start@y ingmechanism maybe supplied, Such ade'- viceisi-illustrated' inv Figs; 2 and 3. In association Withoneof theA bearings 27 ofthe" shaft 12, there is` mounted on the latter a ratchet Wheel 28, and? a cooperating ratchet lever 29is`pivotal`ly, mounted on' the bearing pedestal for oscillation on an axis 29d, past theend of'the shaft and the ratchet Wheel. The ratchet lever carries the ratchet dog 30 for engagement Withrthe teeth of the ratchet; Wheel 28- so that, by manualioscillation of` the lever 29; theshaft' 12 may be given its initial rotation, the lever-'29 and dogSOcooperating 'with' the` ratchet Wheel in' the manner of a feeding device.`

Fory starting` the compressor` from stand still', the compresson casing firstl closed? by closing the valvesV 161 andfl' and the shaft- Y glandsin the manner,v explained above, then the-exhaustingdeviceis set inoperation Vand the air Withdrawn fromA the casing. ThenV by: operationA offthe starting mechanism, the

shaft" is given` initial rotary movement, whereupon the motorv may be switched inl and thefmachine brought up to,v speed With thev normal starting torque of' the motor. Thus simple motors` oftheY induction or 'squirrel cage induction types are rendered' available for the' operation of; rotary7- compressors; After the compressor has been brought upV to speed thevalves 17 and lagre opened, thelexhausting devicelS turned' off, and the cam' ring 25reversedv to permit the cam collar- 24-I bein-gl retracted andthe shaft freed from` the constraint" ofE the gasket 22.

VV-'hat- I claim is:

1i T-he combination with aA gasrcompressor having a casing enclosing a rotor with its drive shaft passingythroughthe casing, of anadjustable gland for forming a seal between the-shaft and casing to prevent ingress of atmosphere, and `means for exhausting contained gases from the casing While the rotor isstationary. Y

2. The combination` specili'ed in claim. 1` together withk a motor` for drivingy the rotor and means for starting the rotor independently of pov'erA from the motor.

3. The combination With a gas compressor having a casing containing a rotor and provided with inlet, outlet and shaft openings, of means for closing said openings to prevent ingress of fluid therethrough, and' means for exhausting contained gas from the casing While the rotor is stationary.

Ll. The combination with compressor apparatus including a casing, an operating shaft disposed in the same and extending through a: ivall thereof, and means for exhausting the fluid contents of. said casing, of fluid-sealing means interposed lbet-veen said casing and shaft, and means associated with said liiuid-sealing means for' effecting movement of the same into or outL of sealin relation with respecty to said casing an shaft;

5. The combination with compressor ap-V paratus including a casing, an operating shaftV disposed in the same and extending through.

about' said shaft at said" Wall and' arranged for seating on said shaft With the pressure exteriorly of said casing, and means. for effecting movement of said valve means into or out of' firm seating. engagement With respect tosaidshaft.

6; The combination with compressor apparatus Y including a casing, an operating shaft disposed inthe same and extending through a Wall thereof,` and means for exhausting the fluid contents of said casing, of {luidt-sealing means interposed between said casing and shaft and including a flexible anfnular element' disposed about said shaft' With itsouter edge infsealing relationfvvithV respect to said'casingyand with its inner edge flexed outwardly beyond the plane of the outer edge and engaging said shaft by. virtue of such tlexure, and means cooperablevwithsaid elementV for increasing the degree of'iiexure thereof to place said inner edge into firm sealing relation with respert t'ovsaid shaft.

7; The combination with compressor ap: paratus including a,v casing,` an operating shaftl disposed in 'the same, and,Y extending through a Wall thereof', and means, for exhaustingY the fluid contents of said casing, of' flexible means interposed between said casingzand shaft at said WallV and operatingv uponbeingilexed to provide a. Huid-,seal be.` tweeny said' casingand shaft, an elementdis'- posed about saidshaft formovement axially thereof and cooperable with said means upon such movement to flex the latter into sealing position, and means cooperable with said element for effectingr such movement thereof.

8. The combination with compressor apparatus including a casing, an operatingr shaft disposed in the same and extending through a Wall thereof, and means for exhausting the fluid contents of said casing, of sealing means interposed between said casing and shaft and supported for movement into and out of sealing relation with respect thereto, and actuating means for said sealing means comprising a part disposed around said shaft for movement axially thereof and for engagement with said sealing means upon such axial movement to effect movement of the latter into sealing position and a second part disposed about said shaft for rotary movement about the axis thereof and for coaction with said firstnamed part upon such rotary movement to effect such axial movement of the latter.

9. The combination with compressor apparatus including a casing, an operating shaft disposed in the same and extending through a Wall thereof, and means for exhausting the fluid contents of said casing, of means interposed between said casing and shaft and including an element arranged about said shaft for clamping engagement therewith and operable upon such engagement to provide 'a Huid-seal between said casing and shaft and means cooperable with said element to effect movement thereof into or out of such engagement with said shaft.

In testimony whereof I have hereunto subscribed my name at Zurich, Switzerland, this 27th day of July, A. D. 1926.

W. VAN RIJSWIJK. 

